Driving circuit and a method for driving a display panel having a touch panel

ABSTRACT

A driving circuit configured to drive a display panel having a touch panel is provided. The driving circuit includes a signal generating circuit, a sensor driving circuit, and a source driving circuit. The signal generating circuit modulates a plurality of voltage signals on a first driving signal and a second driving signal, and drives the gate lines with the modulated first driving signal and the modulated second driving signal during a sensing period. The sensor driving circuit modulates the voltage signals on a third driving signal, and drives the sensor pads with the modulated third driving signal during the sensing period. The data lines are controlled to be electrically floating during the sensing period. In addition, a method for driving a display panel having a touch panel is also provided.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefits of U.S. provisionalapplication Ser. No. 62/207,366, filed on Aug. 19, 2015. The entirety ofthe above-mentioned patent application is hereby incorporated byreference herein and made a part of this specification.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention generally relates to an electronic circuit and a methodfor driving an apparatus, in particular, to a driving circuit and amethod for driving a display panel having a touch panel.

2. Description of Related Art

In this information era, reliance on electronic products is increasingday by day. The electronic products including notebook computers, mobilephones, personal digital assistants (PDAs), digital walkmans, and so onare indispensable in our daily lives. Each of the aforesaid electronicproducts has an input interface for a user to input his or her command,such that an internal system of each of the electronic productspontaneously runs the command. At this current stage, the most commoninput interface includes a keyboard and a mouse.

From the user's aspect, it is sometimes rather inconvenient to use theconventional input interface including the keyboard and the mouse.Manufacturers aiming to resolve said issue thus start to equip theelectronic products with touch input interfaces, e.g. touch pads ortouch panels, so as to replace the conditional keyboards and mice. Atpresent, the users' commands are frequently given to the electronicproducts by physical contact or sensing relationship between users'fingers or styluses and the touch input interfaces. For instance, acapacitive touch input interface characterized by a multi-touch sensingfunction is more user-friendly than the conventional input interface andthus gradually becomes more and more popular.

However, when a touch panel is embedded into a display panel, parasiticcapacitances may be generated therebetween. The parasitic capacitanceswould have an impact on touch operation and reduce display quality.Hence, how to reduce the parasitic capacitances between the touch paneland the display panel to make a display touch apparatus havesatisfactory touch operation and good display quality without increasingthe manufacturing costs is one of the most important topics in thepertinent field.

SUMMARY OF THE INVENTION

Accordingly, the invention is directed to a driving circuit and a methodfor driving a display panel having a touch panel, capable of reducingparasitic capacitances.

The invention provides a driving circuit configured to drive a displaypanel having a touch panel. The driving circuit includes a signalgenerating circuit, a sensor driving circuit, and a source drivingcircuit. The signal generating circuit is coupled to gate lines of thedisplay panel. The signal generating circuit modulates a plurality ofvoltage signals on a first driving signal and a second driving signal,and drives the gate lines with the modulated first driving signal andthe modulated second driving signal during a sensing period. The sensordriving circuit is coupled to sensor pads of the touch panel. The sensordriving circuit modulates the voltage signals on a third driving signal,and drives the sensor pads with the modulated third driving signalduring the sensing period. The source driving circuit is coupled to datalines of the display panel. The data lines are controlled to beelectrically floating during the sensing period.

In an embodiment of the invention, waveforms of the modulated firstdriving signal, the modulated second driving signal, and the modulatedthird driving signal are substantially identical.

In an embodiment of the invention, the signal generating circuitincludes a gate driver circuit and a first signal modulation circuit.The gate driver circuit is coupled to the gate lines. The gate drivercircuit operates between the modulated first driving signal and themodulated second driving signal during the sensing period, and outputsthe modulated first driving signal and the modulated second drivingsignal to the gate lines. The first signal modulation circuit is coupledto the gate driver circuit. The first signal modulation circuit receivesthe voltage signals, and modulates the voltage signals on the firstdriving signal and the second driving signal.

In an embodiment of the invention, the first signal modulation circuitincludes a first modulation channel and a second modulation channel. Thefirst modulation channel is coupled to the gate driver circuit. Thefirst modulation channel receives the voltage signals, and modulates thevoltage signals on the first driving signal. The second modulationchannel is coupled to the gate driver circuit. The second modulationchannel receives the voltage signals, and modulates the voltage signalson the second driving signal.

In an embodiment of the invention, each of the first modulation channeland the second modulation channel includes a capacitor and a multiplexercircuit. The capacitor is coupled to the gate driver circuit. Thecapacitor modulates the voltage signals on the first driving signal orthe second driving signal. The multiplexer circuit is coupled to thegate driver circuit via the capacitor. The multiplexer circuit iscontrolled to sequentially transmit the voltage signals to the capacitorby a plurality of first control signals.

In an embodiment of the invention, the sensor driving circuit includes asecond signal modulation circuit. The second signal modulation circuitis coupled to the sensor pads. The second signal modulation circuitreceives the voltage signals, and modulates the voltage signals on thethird driving signal.

In an embodiment of the invention, the second signal modulation circuitincludes a plurality of third modulation channels. The third modulationchannels are coupled to the sensor pads. The third modulation channelsreceive the voltage signals, and modulate the voltage signals on thethird driving signal.

In an embodiment of the invention, the sensor pads are grouped intoactive sensor pads and non-active sensor pads during the sensing period.The third modulation channels coupled to the non-active sensor pads arecontrolled to sequentially transmit the voltage signals to the touchpanel by a plurality of first control signals.

In an embodiment of the invention, the third modulation channels coupledto the active sensor pads are controlled to transmit sensing signals toa determination circuit by the first control signals.

In an embodiment of the invention, each of the third modulation channelsincludes a multiplexer circuit. The multiplexer circuit is coupled tothe display panel. The multiplexer circuit is controlled to sequentiallytransmit the voltage signals to the display panel or transmit sensingsignals to a determination circuit by the first control signals.

In an embodiment of the invention, the source driving circuit is coupledto the data lines of the display panel via a switch circuit. The switchcircuit is controlled to electrically float the data lines by a secondcontrol signal during the sensing period.

In an embodiment of the invention, the source driving circuit is coupledto the data lines of the display panel via a plurality of multiplexercircuits. Outputs of the multiplexer circuits are controlled to beturned off to electrically float the data lines by the signal generatingcircuit during the sensing period.

The invention provides a method for driving a display panel having atouch panel. The display panel includes a plurality of gate lines and aplurality of data lines. The touch panel includes a plurality of sensorpads. The method includes: modulating a plurality of voltage signals ona first driving signal, a second driving signal, and a third drivingsignal during a sensing period; driving the gate lines with themodulated first driving signal and the modulated second driving signalduring the sensing period, and driving the sensor pads with themodulated third driving signal during the sensing period; andcontrolling the data lines to be electrically floating during thesensing period.

In an embodiment of the invention, waveforms of the modulated firstdriving signal, the modulated second driving signal, and the modulatedthird driving signal are substantially identical.

In an embodiment of the invention, the step of modulating the voltagesignals on the first driving signal, the second driving signal, and thethird driving signal includes: sequentially transmitting the voltagesignals to a gate driver circuit to modulate the voltage signals on thefirst driving signal and the second driving signal according to aplurality of first control signals.

In an embodiment of the invention, the sensor pads are grouped intoactive sensor pads and non-active sensor pads during the sensing period.The step of modulating the voltage signals on the first driving signal,the second driving signal, and the third driving signal includes:sequentially transmitting the voltage signals to the non-active sensorpads to modulate the voltage signals on the third driving signalaccording to a plurality of first control signals.

In an embodiment of the invention, the step of driving the gate lines ofthe display panel with the modulated first driving signal and themodulated second driving signal during the sensing period, and drivingthe sensor pads of the touch panel with the modulated third drivingsignal during the sensing period includes: transmitting sensing signalsof the active sensor pads to a determination circuit by the firstcontrol signals.

In an embodiment of the invention, the data lines are coupled to aswitch circuit. The step of controlling the data lines to beelectrically floating during the sensing period includes: controllingthe switch circuit to electrically float the data lines according to asecond control signal during the sensing period.

In an embodiment of the invention, the data lines are coupled to aplurality of multiplexer circuits. The step of controlling the datalines to be electrically floating during the sensing period includes:controlling outputs of the multiplexer circuits to be turned off toelectrically float the data lines during the sensing period.

According to the above descriptions, the plurality of voltage signalsare modulated on the first driving signal, the second driving signal andthe third driving signal in exemplary embodiments. The gate lines andthe sensor pads are driven by the modulated driving signals, and thedata lines are controlled to be electrically floating during the sensingperiod. Therefore, the parasitic capacitances are reduced.

To make the above features and advantages of the present disclosure morecomprehensible, several embodiments accompanied with drawings aredescribed in detail as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

FIG. 1 illustrates a schematic diagram of a touch panel and a sensordriving circuit according to an embodiment of the invention.

FIG. 2 illustrates a schematic waveform of a signal for driving sensorpads according to an embodiment of the invention.

FIG. 3 illustrates a schematic diagram of parasitic capacitances betweensensor electrodes and panel elements according to an embodiment of theinvention.

FIG. 4 illustrates an equivalent circuit diagram of the parasiticcapacitances depicted in FIG. 3.

FIG. 5 illustrates schematic waveforms of signals for driving sensorpads and panel elements according to an embodiment of the invention.

FIG. 6 illustrates a schematic diagram of a display touch apparatushaving a low temperature poly-silicon (LTPS) touch panel according to anembodiment of the invention.

FIG. 7 illustrates a schematic diagram of a display touch apparatushaving an amorphous silicon (a-Si) touch panel according to anembodiment of the invention.

FIG. 8 illustrates a schematic diagram of a display touch apparatusaccording to an embodiment of the invention.

FIG. 9 illustrates a block diagram of a determination circuit accordingto an embodiment of the invention.

FIG. 10 is a flowchart illustrating steps in a method for driving adisplay panel having a touch panel according to an embodiment of theinvention.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the present preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings.

Wherever possible, the same reference numbers are used in the drawingsand the description to refer to the same or like parts.

The term “coupling/coupled” used in this specification (includingclaims) of the disclosure may refer to any direct or indirect connectionmeans. For example, “a first device is coupled to a second device”should be interpreted as “the first device is directly connected to thesecond device” or “the first device is indirectly connected to thesecond device through other devices or connection means.” In addition,the term “signal” can refer to a current, a voltage, a charge, atemperature, data, electromagnetic wave or any one or multiple signals.

FIG. 1 illustrates a schematic diagram of a touch panel and a sensordriving circuit according to an embodiment of the invention. FIG. 2illustrates a schematic waveform of a signal for driving sensor padsaccording to an embodiment of the invention. Referring to FIG. 1 andFIG. 2, a touch panel 300 of the present embodiment includes a pluralityof sensor pads 310. The sensor pads 310 are arranged in an array. Asensor driving circuit 120 is coupled to the sensor pads 310. The sensordriving circuit 120 drives the sensor pads 310 with a modulated drivingsignal as illustrated in FIG. 2 during a sensing period in the presentembodiment.

To be specific, a whole common electrode of a display panel is dividedinto the plurality of sensor pads 310 in the present embodiment. In adisplay period, the sensor pads 310 serve as common electrodes. In thesensing period, the sensor pads 310 serve as sensor electrodes. Thesensor driving circuit 120 modulates voltage signals VML, VMM and VMH ona driving signal VCOM to generate the modulated driving signal asillustrated in FIG. 2. In the present embodiment, the driving signal

VCOM may be a signal applied to the common electrodes in the displayperiod. When the sensor pads 310 serve as the sensor electrodes in thesensing period, the sensor driving circuit 120 drives the sensor pads310 with the modulated driving signal 230 via sensor trace 312. Next, ananalog-front-end (AFE) circuit calculates capacitive variations of eachof the sensor pads 310 relative to ground, so as to determine whether atouch event happens.

In the present embodiment, the touch panel 300 may be embedded into thedisplay panel in a manner of in-cell or on-cell, and the invention isnot limited thereto.

Enough teaching, suggestion, and implementation illustration for theaforesaid touch panel may be obtained with reference to common knowledgein the related art, which is not repeated hereinafter.

FIG. 3 illustrates a schematic diagram of parasitic capacitances betweensensor electrodes and panel elements according to an embodiment of theinvention. Referring to FIG. 3, sensor pads SP-A, SP-B, SP-C and SP-Dare disposed above a plurality of data lines DL[n] to DL[n+3], aplurality of gate lines GL[n] to GL[n+2], and a plurality of pixelelectrodes 520, where n is an integer large than or equal to 1. Each ofthe sensor pads SP-A, SP-B, SP-C and SP-D includes a plurality ofsub-common electrodes 521 in the present embodiment. The plurality ofsub-common electrodes 521 are electrically connected to form a singlesensor pad, e.g. the sensor pad SP-A, SP-B, SP-C or SP-D. In addition,sensor trances ST[n] and ST[n+1] connects the sensor pads SP-A, SP-B,SP-C and SP-D and a sensor driving circuit. In the present embodiment,parasitic capacitances Csd, Cdg, Csg and Csp may be generated among thesensor electrodes and the panel elements. For example, the parasiticcapacitance Csd may be generated between the sensor electrode and thedata line, the parasitic capacitance Cdg may be generated between thedata line and the gate line, the parasitic capacitance Csg may begenerated between the sensor electrode and the gate line, and theparasitic capacitance Csp may be generated between the sensor electrodeand the pixel electrode.

FIG. 4 illustrates an equivalent circuit diagram of the parasiticcapacitances depicted in FIG. 3. FIG. 5 illustrates schematic waveformsof signals for driving sensor pads and panel elements according to anembodiment of the invention. Referring to FIG. 1, FIG. 4 and FIG. 5, theparasitic capacitances Csd and Cdg are coupled in series in the presentembodiment. When the sensor driving circuit 120 drives the sensor pads310 with the modulated third driving signal 230 via the sensor trace312, the data lines, e.g. DL[n] to DL[n+3], are controlled to beelectrically floating during the sensing period. In the presentembodiment, the pixel electrodes 520 may also be controlled to beelectrically floating during the sensing period. At the same time, afirst driving signal VGH and a second driving signal VGL are modulatedwith the voltage signals VML, VMM and VMH to generate the modulatedfirst driving signal 210 and the modulated second driving signal 220,respectively. The gate lines, e.g. GL[n] to GL[n+2], are driven by themodulated first driving signal 210 and the modulated second drivingsignal 220 during the sensing period. In the present embodiment, thefirst driving signal VGH and the second driving signal VGL may besignals that are respectively applied to a VGH power line and a VGLpower line in the display period.

In the present embodiment, the waveforms of the modulated first drivingsignal 210, the modulated second driving signal 220, and the modulatedthird driving signal 230 are substantially identical as shown in FIG. 5.For example, during the sensing period, each of the modulated firstdriving signal 210, the modulated second driving signal 220, and themodulated third driving signal 230 may have a plurality of stepwaveforms located in corresponding timing. In the present embodiment,since the data lines are electrically floating, and the waveforms of thefirst driving signal VGH and the second driving signal VGL are modulatedto be similar to that of the third driving signal VCOM during thesensing period, the parasitic capacitances Csd and Cdg are effectivelyreduced. In the present embodiment, voltage levels of the first drivingsignal VGH, the second driving signal VGL and the third driving signalVCOM may be the same or different according to design requirements, andthe invention is not limited thereto.

FIG. 6 illustrates a schematic diagram of a display touch apparatushaving a low temperature poly-silicon (LTPS) touch panel according to anembodiment of the invention. Referring to FIG. 6, data lines DL arecontrolled by multiplexer circuits 634 on a LTPS touch panel 640, andgate lines GL are controlled by a gate control circuit 614 in thepresent embodiment. Operation voltages and control/driving signals ofthe multiplexer circuits 634 and the gate control circuit 614 areprovided by an external gate driver 612. The gate driver 612 is arrangedout of the LTPS touch panel 640. The gate driver 612 controls themultiplexer circuits 634 located on the LTPS touch panel 640 to turn offthe output of the multiplexer circuits 634 during the sensing period,and thus the data lines DL are floating in the present embodiment. Inone embodiment, the outputs SOUT[1] to SOUT[N] of the source driver 632may be coupled to the data lines DL via a switch circuit, and the switchcircuit is controlled to make the data lines DL electrically floating bya control signal during the sensing period, where N is an integer largethan or equal to 4. In the present embodiment, the gate driver 612 alsocontrols the output of the gate control circuit 614 located on the LTPStouch panel 640 to turn off the gate terminals of the thin filmtransistors, e.g. 300 depicted in FIG. 3, during the sensing period, andthus the pixel electrodes, e.g. 520 depicted in FIG. 3, are floating inthe present embodiment. In the present embodiment, the waveforms of thefirst driving signal VGH and the second driving signal VGL are modulatedto be similar to that of the third driving signal VCOM during thesensing period as illustrated in FIG. 5, and thus the parasiticcapacitances Csd and Cdg are effectively reduced.

FIG. 7 illustrates a schematic diagram of a display touch apparatushaving an amorphous silicon (a-Si) touch panel according to anembodiment of the invention. Referring to FIG. 7, data lines DL and gatelines GL are respectively controlled by an external source driver 730and an external gate driver 710 in the present embodiment.

The source driver 730 and the gate driver 710 are arranged out of thea-Si touch panel 740. In the present embodiment, the source driver 730is coupled to the data lines DL of the a-Si touch panel 740 via a switchcircuit 750. The switch circuit 750 is controlled to electrically floatthe data lines DL by a control signal S2 during the sensing period. Inthe present embodiment, the control signal S2 may be provided by thesource driver 730, the gate driver 710, a timing control circuit, orother similar circuits according to design requirements, and it is notlimited in the invention. In the present embodiment, the gate driver 710also turns off the gate terminals of the thin film transistors, e.g. 300depicted in FIG. 3, via the gate lines GL during the sensing period, andthus the pixel electrodes, e.g. 520 depicted in FIG. 3, are floating inthe present embodiment. In the present embodiment, the waveforms of thefirst driving signal VGH and the second driving signal VGL are modulatedto be similar to that of the third driving signal VCOM during thesensing period as illustrated in FIG. 5, and thus the parasiticcapacitances Csd and Cdg are effectively reduced.

FIG. 8 illustrates a schematic diagram of a display touch apparatusaccording to an embodiment of the invention. Referring to FIG. 8, thedisplay touch apparatus 800 of the present embodiment includes a drivingcircuit 830 and a display panel 850. The display panel 850 includes atouch panel 840. The driving circuit 830 is configured to drive thedisplay panel 850. The driving circuit 830 includes a signal generatingcircuit 810 and a sensor driving circuit 820. In the present embodiment,the signal generating circuit 810 modulates a plurality of voltagesignals VML, VMM and VMH on a first driving signal VGH and a seconddriving signal VGL, and drives the gate lines, e.g. GL depicted in FIG.6 or FIG. 7, with the modulated first driving signal 210 and themodulated second driving signal 220 during a sensing period. In thepresent embodiment, the sensor driving circuit 820 modulates the voltagesignals VML, VMM and VMH on a third driving signal VCOM, and drives thesensor pads, e.g. SP depicted in FIG. 6 or FIG. 7, with the modulatedthird driving signal 230 during the sensing period. In the presentembodiment, the data lines, e.g. DL depicted in FIG. 6 or FIG. 7, arecontrolled to be electrically floating during the sensing period, andwaveforms of the modulated first driving signal 210, the modulatedsecond driving signal 220, and the modulated third driving signal 230are substantially identical. In addition, the voltage signals VML, VMMand VMH and the driving signals VGH, VGL, VCOM and GND may be providedby a power generator circuit (not shown) in the present embodiment.

To be specific, the signal generating circuit 810 includes a gate drivercircuit 812, a first signal modulation circuit 814, and a controlcircuit 816 in the present embodiment. The gate driver circuit 812 iscoupled to the gate lines. The gate driver circuit 812 operates betweenthe modulated first driving signal 210 and the modulated second drivingsignal 220 during the sensing period, and outputs the modulated firstdriving signal 210 and the modulated second driving signal 220 to thecoupled gate lines. The first signal modulation circuit 814 is coupledto the gate driver circuit 812. The first signal modulation circuit 814receives the voltage signals VML, VMM and VMH, and modulates the voltagesignals VML, VMM and VMH on the first driving signal VGH and the seconddriving signal VGL.

In the present embodiment, the first signal modulation circuit 814includes a first modulation channel 815 and a second modulation channel817. The first modulation channel 815 receives the voltage signals VML,VMM and VMH, and modulates the voltage signals VML, VMM and VMH on thefirst driving signal VGH. The second modulation channel 817 receives thevoltage signals VML, VMM and VMH, and modulates the voltage signals VML,VMM and VMH on the second driving signal VGH. In the present embodiment,each of the first modulation channel 815 and the second modulationchannel 817 includes a capacitor and a multiplexer circuit. Taking thefirst modulation channel 815 for example, the capacitor C1 is coupled tothe gate driver circuit 812. The capacitor C1 modulates the voltagesignals VML, VMM and VMH on the first driving signal VGH. Themultiplexer circuit MUX1 is coupled to the gate driver circuit 812 viathe capacitor C1. The multiplexer circuit MUX1 is controlled tosequentially transmit the voltage signals VML, VMM and VMH to thecapacitor C1 by one of a plurality of control signals S1. Elements andoperations of the second modulation channel 817 may be deduced byanalogy according to descriptions of the first modulation channel 815,and it is not further described herein. In the present embodiment, thecontrol circuit 816 outputs the plurality of control signals S1 tocontrol the multiplexer circuits MUX1 and MUX2. The multiplexer circuitsMUX1 and MUX2 select one of the voltage signals VML, VMM, VMH and GNDaccording to the control signals S1, and thus output the selected signalto the capacitors C1 and C2, respectively.

In the present embodiment, the sensor driving circuit 820 includes asecond signal modulation circuit 822, and the second signal modulationcircuit 822 includes a plurality of third modulation channels 823. Inthe present embodiment, each of the third modulation channels 823includes a multiplexer circuit MUX3. The multiplexer circuits MUX3receive the voltage signals VML, VMM and VMH, and modulate the voltagesignals VML, VMM and VMH on the third driving signal VCOM according tothe plurality of control signals S1.

In the present embodiment, the sensor pads are grouped into activesensor pads and non-active sensor pads during the sensing period. Themultiplexer circuits MUX3 coupled to the non-active sensor pads, i.e.the multiplexer circuits MUX3 located in the non-active sensing region,are controlled to sequentially transmit the voltage signals VML, VMM,VMH, GND and VCOM to the touch panel 840 by the plurality of controlsignals S1. The multiplexer circuits MUX3 coupled to the active sensorpads, i.e. the multiplexer circuits MUX3 located in the active sensingregion, are controlled to transmit sensing signals S3 to a determinationcircuit 900 by the plurality of control signals S1. In the presentembodiment, the determination circuit 900 may include a plurality ofanalog-front-end (AFE) circuits respectively denoted by AFE[a], AFE[b],AFE[c] and AFE[d], as illustrated in FIG. 9. FIG. 9 illustrates a blockdiagram of a determination circuit according to an embodiment of theinvention. Enough teaching, suggestion, and implementation illustrationfor the aforesaid determination circuit and AFE circuits may be obtainedwith reference to common knowledge in the related art, which is notrepeated hereinafter.

In the present embodiment, the waveforms of the first driving signal VGHand the second driving signal VGL are modulated to be similar to that ofthe third driving signal VCOM during the sensing period as illustratedin FIG. 5, and the data lines, e.g. DL depicted in FIG. 6 or FIG. 7, arecontrolled to be electrically floating during the sensing period.Therefore, the parasitic capacitances Csd and Cdg are effectivelyreduced.

FIG. 10 is a flowchart illustrating steps in a method for driving adisplay panel having a touch panel according to an embodiment of theinvention. Referring to FIG. 6 to FIG. 8 and FIG. 10, the method fordriving the display panel having the touch panel of the presentembodiment is at least adapted to one of the display touch apparatus 600of FIG. 6, the display touch apparatus 700 of FIG. 7, and the displaytouch apparatus 800 of FIG. 8, but the invention is not limited thereto.Taking the display touch apparatus 800 of FIG. 8 for example, in stepS100, the driving circuit 830 modulates a plurality of voltage signalsVML, VMM and VMH on a first driving signal VGH, a second driving signalVGL, and a third driving signal VCOM during a sensing period.

In step S110, the driving circuit 830 drives the gate lines GL with themodulated first driving signal 210 and the modulated second drivingsignal 220 during the sensing period, and drives the sensor pads SP withthe modulated third driving signal 230 during the sensing period. Instep S120, the driving circuit 830 controls the data lines DL to beelectrically floating during the sensing period.

Besides, the method for driving the display panel having the touch paneldescribed in the present embodiment of the invention is sufficientlytaught, suggested, and embodied in the embodiments illustrated in FIG. 1to FIG. 9, and therefore no further description is provided herein.

In summary, in the exemplary embodiment of the invention, the firstdriving signal and the second driving signal are modulated to drive thegate lines of the display panel during the sensing period, and the thirddriving signal is also modulated to drive the sensor pads of the touchpanel. The waveforms of the modulated first driving signal, themodulated second driving signal, and the modulated third driving signalare substantially identical. The data lines of the display panel arecontrolled to be electrically floating during the sensing period.Therefore, the parasitic capacitances between the sensor pads and thedata lines and the parasitic capacitances between the data lines and thegate lines are effectively reduced.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the present inventioncover modifications and variations of this invention provided they fallwithin the scope of the following claims and their equivalents.

What is claimed is:
 1. A driving circuit configured to drive a displaypanel having a touch panel, and the driving circuit comprising: a signalgenerating circuit, coupled to gate lines of the display panel,modulating a plurality of voltage signals on a first driving signal anda second driving signal, and driving the gate lines with the modulatedfirst driving signal and the modulated second driving signal during asensing period; a sensor driving circuit, coupled to sensor pads of thetouch panel, modulating the voltage signals on a third driving signal,and driving the sensor pads with the modulated third driving signalduring the sensing period; and a source driving circuit, coupled to datalines of the display panel, wherein the data lines are controlled to beelectrically floating during the sensing period.
 2. The driving circuitaccording to claim 1, wherein waveforms of the modulated first drivingsignal, the modulated second driving signal, and the modulated thirddriving signal are substantially identical.
 3. The driving circuitaccording to claim 1, wherein the signal generating circuit comprises: agate driver circuit, coupled to the gate lines, operating between themodulated first driving signal and the modulated second driving signalduring the sensing period, and outputting the modulated first drivingsignal and the modulated second driving signal to the gate lines; and afirst signal modulation circuit, coupled to the gate driver circuit,receiving the voltage signals, and modulating the voltage signals on thefirst driving signal and the second driving signal.
 4. The drivingcircuit according to claim 3, wherein the first signal modulationcircuit comprises: a first modulation channel, coupled to the gatedriver circuit, receiving the voltage signals, and modulating thevoltage signals on the first driving signal; and a second modulationchannel, coupled to the gate driver circuit, receiving the voltagesignals, and modulating the voltage signals on the second drivingsignal.
 5. The driving circuit according to claim 4, wherein each of thefirst modulation channel and the second modulation channel comprises: acapacitor, coupled to the gate driver circuit, and modulating thevoltage signals on the first driving signal or the second drivingsignal; and a multiplexer circuit, coupled to the gate driver circuitvia the capacitor, and controlled to sequentially transmit the voltagesignals to the capacitor by a plurality of first control signals.
 6. Thedriving circuit according to claim 1, wherein the sensor driving circuitcomprises: a second signal modulation circuit, coupled to the sensorpads, receiving the voltage signals, and modulating the voltage signalson the third driving signal.
 7. The driving circuit according to claim6, wherein the second signal modulation circuit comprises: a pluralityof third modulation channels, coupled to the sensor pads, receiving thevoltage signals, and modulating the voltage signals on the third drivingsignal.
 8. The driving circuit according to claim 7, wherein the sensorpads are grouped into active sensor pads and non-active sensor padsduring the sensing period, and the third modulation channels coupled tothe non-active sensor pads are controlled to sequentially transmit thevoltage signals to the touch panel by a plurality of first controlsignals.
 9. The driving circuit according to claim 7, wherein the thirdmodulation channels coupled to the active sensor pads are controlled totransmit sensing signals to a determination circuit by the first controlsignals.
 10. The driving circuit according to claim 7, wherein each ofthe third modulation channels comprises: a multiplexer circuit, coupledto the display panel, and controlled to sequentially transmit thevoltage signals to the display panel or transmit sensing signals to adetermination circuit by the first control signals.
 11. The drivingcircuit according to claim 1, wherein the source driving circuit iscoupled to the data lines of the display panel via a switch circuit, andthe switch circuit is controlled to electrically float the data lines bya second control signal during the sensing period.
 12. The drivingcircuit according to claim 1, wherein the source driving circuit iscoupled to the data lines of the display panel via a plurality ofmultiplexer circuits, and outputs of the multiplexer circuits arecontrolled to be turned off to electrically float the data lines by thesignal generating circuit during the sensing period.
 13. A method fordriving a display panel having a touch panel, wherein the display panelcomprises a plurality of gate lines and a plurality of data lines, thetouch panel comprises a plurality of sensor pads, and the methodcomprising: modulating a plurality of voltage signals on a first drivingsignal, a second driving signal, and a third driving signal during asensing period; driving the gate lines with the modulated first drivingsignal and the modulated second driving signal during the sensingperiod, and driving the sensor pads with the modulated third drivingsignal during the sensing period; and controlling the data lines to beelectrically floating during the sensing period.
 14. The methodaccording to claim 13, wherein waveforms of the modulated first drivingsignal, the modulated second driving signal, and the modulated thirddriving signal are substantially identical.
 15. The method circuitaccording to claim 13, wherein the step of modulating the voltagesignals on the first driving signal, the second driving signal, and thethird driving signal comprises: sequentially transmitting the voltagesignals to a gate driver circuit to modulate the voltage signals on thefirst driving signal and the second driving signal according to aplurality of first control signals.
 16. The method circuit according toclaim 13, wherein the sensor pads are grouped into active sensor padsand non-active sensor pads during the sensing period, and the step ofmodulating the voltage signals on the first driving signal, the seconddriving signal, and the third driving signal comprises: sequentiallytransmitting the voltage signals to the non-active sensor pads tomodulate the voltage signals on the third driving signal according to aplurality of first control signals.
 17. The method according to claim16, wherein the step of driving the gate lines of the display panel withthe modulated first driving signal and the modulated second drivingsignal during the sensing period, and driving the sensor pads of thetouch panel with the modulated third driving signal during the sensingperiod comprises: transmitting sensing signals of the active sensor padsto a determination circuit by the first control signals.
 18. The methodaccording to claim 13, wherein the data lines are coupled to a switchcircuit, and the step of controlling the data lines to be electricallyfloating during the sensing period comprises: controlling the switchcircuit to electrically float the data lines according to a secondcontrol signal during the sensing period.
 19. The method according toclaim 13, wherein the data lines are coupled to a plurality ofmultiplexer circuits, and the step of controlling the data lines to beelectrically floating during the sensing period comprises: controllingoutputs of the multiplexer circuits to be turned off to electricallyfloat the data lines during the sensing period.